Varicose veins of the lower extremities is one of the most common medical conditions of the adult population. It is estimated that varicose veins affect approximately 25% of adult females and 10% of males. Symptoms include discomfort, aching of the legs, itching, cosmetic deformities, and swelling. If left untreated, varicose veins may cause medical complications such as bleeding, phlebitis, ulcerations, thrombi and lipodermatosclerosis.
Unlike arteries, veins are thin-walled and contain valves that control blood flow. The valves act as one-way flaps that open to allow blood to flow into the deeper veins and close to prevent backflow into the superficial veins. Varicose veins are caused when those valves become incompetent and can no longer prevent the reflux of blood into the superficial veins. Venous pressure builds at the site of the incompetence due to backflow and “pileup” of blood. Because the veins are thin walled and not able to withstand the increased pressure, the veins become dilated, tortuous and engorged.
Traditional treatments for varicosities include both temporary and permanent techniques. Temporary treatments involve use of compression stockings and elevation of the diseased extremities. While providing temporary relief of symptoms, these techniques do not treat the incompetent valves that are the underlying cause of the varicose veins.
Permanent treatments include surgical excision of the diseased segments and occlusion of the vein through chemical or thermal means. These treatment types focus on the elimination of underlying incompetent vein reflux by either removal or occlusion of the veins. Although permanent treatments focus on elimination of reflux, there are drawbacks and complications associated with surgical removal and vein occlusion procedures.
Surgical excision often requires general anesthesia and a long recovery period. Even with its clinical effectiveness, surgical excision is rapidly becoming an outmoded procedure due to the high costs of treatment and risk of complications from surgery. In addition, the cosmetic results are often unsatisfactory due to scarring.
A new thermal treatment option that was recently developed to replace the surgical treatment procedure utilizes thermal energy from either radio frequency (RF) or laser light. The thermal energy from the RF signal or laser is applied to the inner wall of the diseased vein. In reaction to the thermal energy, the vein becomes occluded. Reported recurrence rates are low with relatively fast recovery times. The thermal procedure is done on an outpatient basis with the use of local anesthesia. Although complications are usually minor, in some rare cases, serious dermal burns, focal numbness, vessel perforations and pulmonary emboli have been reported. However, drawbacks of the thermal treatment of varicose veins include the high cost of equipment for the generator and disposables as well as the inability to treat all vein sizes. In addition, the size of the thermal delivery system limits the size of veins that can be treated with this method.
Chemical occlusion, also known as sclerotherapy, is an in-office procedure involving the injection of an irritant chemical into the vein. The chemical acts upon the inner lining of the vein walls causing vessel fibrosis and occlusion of blood flow. Although the chemical occlusion procedure is a popular treatment option, complications can be severe including skin ulceration, anaphylactic reactions and permanent skin staining. Treatment is also limited to veins of a particular size range, typically smaller veins. Other drawbacks include a relatively high recurrence rate due to vessel re-canalization and inability to treat the underlying valve incompetence originating at the saphenous-femoral junction.
The incompetent feeding vein may be deep and angled relative to the skin surface such that it is not visible or palpable. The source of reflux in these deep or non-visible veins often must be eliminated as part of the overall treatment procedure. Traditionally, either ultrasound-guided sclerotherapy or stab avulsion techniques have been used to eliminate the reflux in these deeper veins. As previously described, ultrasound-guided sclerotherapy is often not completely effective in eliminating the reflux source and as a result the treatment may need to be repeated. With stab avulsion, an incision up to 4 to 5 mm long is first made in the skin. Hemostatic forceps or another similar tool is then inserted into the incision and the vein segment is pulled up through the incision. The disadvantage of this technique is the size of the incision which causes unnecessary trauma and unsightly scarring.
In contrast to the above procedures, ambulatory phlebectomy has become a widely accepted medical technique in the treatment of varicose veins, particularly tributaries. Ambulatory phlebectomy is generally used to remove varicosities of the tributary veins that are caused either by greater-saphenous vein reflux or by isolated weakness of the vessel walls without underlying valve incompetency. When greater saphenous vein reflux is the cause of the varicosities, elimination of the reflux source is first performed using thermal, surgical or chemical treatment as described above. Ambulatory phlebectomy is then used as an adjunctive procedure to treat the tributary veins. When varicose tributaries are not directly connected to an incompetent larger vein, ambulatory phlebectomy can be used as the primary treatment procedure.
The ambulatory phlebectomy technique for tributary varicosities involves extraction of the varicose vein segment using small incisions through the skin. Ambulatory phlebectomy has several advantages over more traditional treatment techniques. As a minimally invasive procedure, ambulatory phlebectomy is performed in an outpatient setting using local anesthesia. The small size of the incisions, typically 1 to 2 mm, eliminates the need for skin suturing, improves cosmetic appearance and reduces recovery time. Risk of thromboembolic events and other serious complications are minimal with this technique. In addition, ambulatory phlebectomy can be used to successfully treat tributary varicose veins of almost any size and at almost any anatomical site as long as they are visible and palpable.
One main disadvantage of ambulatory phlebectomy as a varicose vein treatment is the relatively long procedure time. Specifically, the varicose vein is first mapped out on the skin surface. Local or tumescent anesthesia is then injected along the length of the treatment zone. After the injection of anesthesia, the skin is incised using a scalpel or needle. To capture and extract the vein, the scalpel is removed and a surgical hook-like instrument is inserted and positioned under the vein. The vein is grasped and withdrawn. Thus, ambulatory phlebectomy is essentially a blind procedure in which the physician does not know that the correct target vein has been hooked until it is withdrawn through the incision and can be seen. This blind procedure results in inadvertent hooking of other bodily structures such as nerves and can also result in incomplete vein segments being extracted. Often, several attempts at pulling, rotating and twisting the hook tool is required before the vein is successfully engaged. These movements can cause trauma to the surrounding tissue and significant post-procedural bruising.
The use of surgical hooks, forceps and toothed clamps to retrieve varicose vein segments is well known in the art. Perhaps the most well known of these devices is the Muller phlebectomy hooks, which were first introduced to the market in the 1970s. Typically, the hook is inserted into a previously created incision. The hook is rotated to grasp the vein and then pulled out of the incision. Thus, the Muller design required two separate surgical instruments to perform ambulatory phlebectomy: a scalpel for forming the incision; and a hook for engaging and retrieving the vein.
A supposed improvement on the Muller technique was disclosed by Suval in U.S. Pat. Nos. 5,792,168 and 5,758,665, both of which are incorporated herein by reference. Suval discloses a trigger-activated surgical device for varicose vein removal in the '168 patent. A solid needle at the end of an elongated shaft is positioned adjacent to the vein. When the trigger is depressed, the vein is gripped from the outside between the distal end of the barrel and the flat proximal surface of the needle. In the '665 patent, Suval teaches a method for engaging and removing a vein using a single surgical instrument that is placed adjacent to the vein.
While Suval teaches a design for engaging and removing the vein by using a single instrument, the technique still suffers from the same drawbacks that are present in any ambulatory phlebectomy. Because the device is positioned adjacent to the vein rather than within the vein, there is no visual confirmation that the engaged structure is actually a vein until it is brought to the skin surface. Thus, the phlebectomy procedure using Suval's device and method remains a blind procedure with the inherent risks of inadvertently extracting a nerve or other non-targeted structure. As with traditional phlebectomy hooks, Suval's device may need to be rotated, pulled, twisted and otherwise maneuvered to successfully capture the vein for extraction. Since Suval's device cannot precisely target the vein, repeated attempts may be required before the vein is successfully hooked and extracted resulting in extended procedural time.
Perhaps the most serious drawback of ambulatory phiebectomy including the Suval procedure is the risk of inadvertently hooking nerves or other body tissue. Because nerves and veins are often located in close proximity to each other and often have the same appearance, it is difficult to distinguish a nerve either tactilely or visually when using a traditional phlebectomy hook. As a result, a nerve may be mistakenly hooked and withdrawn during an ambulatory phlebectomy procedure, resulting in temporary or even permanent nerve damage to the patient. Suval's teaching does not include any mechanism for identifying the correct positioning prior to removal from the incision.
Therefore, it is desirable to provide an improved device and method for use in ambulatory phlebectomy that eliminates the need for a phlebectomy hook, reduces procedure time, reduces cosmetic imperfections and provides the capability to check for correct positioning prior to removal of the target vein.